The present invention relates to vehicular diagnostic tools, and more particularly, to a diagnostic tool having a parsed database of code descriptors to allow storage of multiple vehicle codes in a smaller, non-compressed database.
Vehicular diagnostic tools are operative to receive diagnostic codes from a vehicle on-board computer. An example the codes may be diagnostic trouble codes (DTCs), such as are used in the OBDI and OBDII diagnostic code protocols. Code readers typically operate to simply read and display the vehicle codes, e.g. “P106”. In some cases the code readers may also display the engine condition that corresponds to the received code, e.g. “P109 Engine Temperature High”. Scan tools are typically include more functionality then code readers in that they may also generate commands for communication to a vehicle on-board computer to regulate the operation of the on-board computer and the nature of the received information. Both code readers and scan tools are considered vehicle diagnostic tools within the scope of the present disclosure.
Where the diagnostic tool is operative to display descriptive data corresponding to the received automotive code, a database of the descriptive data or descriptors corresponding to each received code is commonly stored in memory. Insofar as there may be hundreds or thousands of possible codes for each type of vehicle, the database capacity requirements may be enormous if the tool is intended to be used for multiple types of vehicles.
Many earlier diagnostic tools were specific to certain types of vehicles or manufacturers. This was necessary to avoid prohibitive memory requirements to store code descriptors for many different vehicles. Later scan tools included replaceable cartridges that may be connected to the diagnostic tool. The cartridges may include codes and associated descriptive data specific to the type or model vehicle under test. As such, multiple cartridges might be used with a single diagnostic tool, with each cartridge storing code and descriptors for a specific vehicle(s). While this approach provided increased functionality of the diagnostic tools, it required users to purchase multiple cartridges. Further, such cartridges commonly have limited update capacity and may be subject to mechanical failures in relation to pin connectors and the like. Accordingly, such cartridge based systems, while useful to address deficiencies in the earlier diagnostic tools, remain subject to various limitations in use, reliability, and update capacity.
Other diagnostic tools have taken a different approach to providing multi-vehicle functionality while avoiding producing the inherent limitations of cartridge based devices. Such systems have used data compression techniques to store multi-vehicle codes and descriptors within a smaller memory disposed in the diagnostic tool. As a result, the tool can interface with a variety of different type vehicles without the need to utilize of interchangeable cartridges. While such handheld tools improved upon the functionality of cartridge based diagnostic tools, they remain subject to various limitations. For example, such systems require decompression of descriptive data associated with the vehicle under test. Moreover, the decompression procedure utilizes processing resources and adds to complexity of the tool. Further, while such devices can possibly be upgraded to load additional information into memory, the information must be loaded in accordance with the same compression techniques that are utilized to decompress the descriptive data in relation to the received vehicle codes.
The present invention is directed to a diagnostic tool, suitable for use with multiple types of vehicles, but without the requirement for either interchangeable cartridges or data compression techniques to store diagnostic codes or descriptors. As described more fully below, the present invention utilizes operating and program techniques that significantly reduce the database size requirements or storing code descriptors, without the need for data compression techniques, or the use of replaceable, vehicle specific cartridges. As such, the present invention avoids the need for brute force processing of received diagnostic codes, while maintaining multi-vehicle functionality in a simple, easy to use device.